Coast Guard officials will likely use a remotely operated vehicle - known as an ROV - to obtain photos and video of the Provincetown-based fishing vessel Twin Lights, which sank Sunday.

Jean Frottier, 69, of Wellfleet is believed to have been aboard his 40-foot vessel when it capsized at around 11:30 a.m. two miles north of Provincetown. Crew member Eric Rego was rescued by the Provincetown fishing vessel Glutton, which was nearby when the Twin Lights turned over.

On Sunday, rescue swimmers were unable to immediately reach the wheelhouse of the capsized Twin Lights due to the depth, Coast Guard spokesman Rob Simpson said. State police divers, who arrived after the boat had begun to sink, were also stymied by the deep and turbulent waters.

On Monday state police divers located the Twin Lights with a sidescan sonar dragged behind a Coast Guard boat, Coast Guard Station Provincetown chief John Harker said. The vessel is in 198 feet of water and within state boundaries, Harker said.

The Coast Guard has not yet given a reason for the capsizing and sinking.

Fishermen who knew Frottier told the Times Monday they had learned from fishermen at the scene that Frottier's scallop dredge had become entangled in a line of lobster traps, and that the vessel became top-heavy and began taking on water as he attempted to get the equipment untangled.

When Frottier used the vessel's engine to untangle the line from the dredge the boat suddenly capsized.

“The wheels are definitely turning,” Harker said. “Now we're looking at getting down to the vessel. The current is some of the worst in the Northeast and when you add on 200 feet for diving, it's a very technical operation.”